#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>

int Sum(int start,int end)
{
    int sum = 0;
    for(int i = start; i <= end; i++)
    {
        sum += i;
    }
    return sum;
}

int main()
{
    int start = 1;
    int end = 100;
    int n = Sum(start,end);
    printf("the result is %d\n",n);
    return 0;
}
